Why is my hair shedding so much as a teen?

Some hair shedding during the teenage years is completely normal. Hair naturally goes through different stages of growth, rest, and shedding, so losing some strands each day is expected. But if you are suddenly seeing much more hair on your pillow, clothes, or in the shower, there could be another reason behind it.
Puberty and hormonal changes can affect the hair-growth cycle. Stress, poor sleep, rapid weight loss, restrictive eating, or not getting enough protein, iron, vitamin D, or other nutrients can also trigger increased shedding. It is also common to notice more hair fall a few months after a fever, infection, illness, or a particularly stressful period.